Answer:
The approximate number of decays this represent is
Explanation:
From the question we are told that
The amount of Radiation received by an average american is 
The source of the radiation is 
Generally

Therefore 
Also 
Therefore 
An Average american weighs 88.7 kg
The total energy received is mathematically evaluated as

Cross-multiplying and making x the subject


Therefore the total energy deposited is 
The approximate number of decays this represent is mathematically evaluated as
N = 
Where n is the approximate number of decay
Substituting values
The period of the wave would be halved
Answer:
If a man starts running on a boat with an acceleration a with respect to the boat, there is no external force that acts on the Boat+Man system
<h2>The temperature of the air is 66.8° C</h2>
Explanation:
From the Newton's velocity of sound relationship , the velocity of sound is directly proportional to the square root of temperature .
In this case The velocity of sound = frequency x wavelength
= 798 x 0.48 = 383 m/sec
Suppose the temperature at this time = T K
Thus 383 ∝
I
The velocity of sound is 329 m/s at 273 K ( given )
Thus 329 ∝
II
Dividing I by II , we have
= 
or
= 1.25
and T = 339.8 K = 66.8° C